I've been trying to source the correct paint code for my 1947 BM.
As I'm in the UK the DuPont codes are pretty much useless but managed to find some RAL conversions which can be mixed by any decent bodyshop supplier. Here are my findings (hope they can help others)...
Prior to Mid 1949:
IH50 / PPG 70019/ Dupont 7410 / Ral 3003
Mid 1949 or later:
IH 1102B (no PPG, Dupont or RAL that I can find)
IH 2150 / PPG 71310 / Dupont 96766